Microsoft Delivers Final Peek at IE9 Preview Before September Beta

Microsoft has made key improvements to its next-generation browser in the fourth and final platform preview of the Internet Explorer 9 technology prior to its beta release. Improvements include integrating the "Chakra" JavaScript engine into the IE9 browser.

Leading
up to a beta version of Internet Explorer (IE) 9 in September, Microsoft
has released another Platform Preview of the browser that features native
JavaScript integration, hardware-accelerated HTML5 and much improved Acid3
scores, among other enhancements.
At
the Microsoft Financial Analyst Meeting on July 29, Microsoft's chief operating
officer, Kevin Turner, said Microsoft will deliver a beta
of IE9 in September.

"We're
really excited about IE9, which will be beta and coming out in September,"
Turner said.

Since
announcing its plans to deliver a next-generation browser known as IE9 at its
MIX 2010 conference in March, Microsoft has released preview versions of IE9
for developers to test about every eight weeks or fewer. A new Platform Preview
release now enables the company to make that eight-week time frame for getting
a beta out in September.
Going
by the progress Microsoft has made in its previous Platform Previews, you might
expect to see enhancements to the company's "same markup" strategy,
improved browser performance, greater compatibility and compliance with
standards, enhanced HTML5 support, more test cases, and improved Acid3 test
scores. With IE9 Platform
Preview 4 you get all that and more.
Yet
perhaps the standout feature of the several new and improved ones is the
integration of the IE9 JavaScript engine into the browser itself rather than
being simply bolted on.
In
an
Aug. 4 blog post on the new preview, Dean Hachamovitch, Microsoft's general
manager of Internet Explorer, said:
"The
fourth Platform Preview moves the new
JavaScript engine, codenamed Chakra, inside IE9 and brings them together
into one single, integrated system.
"Through
this deep integration, the performance of real world websites significantly
improves, and IE9 becomes the first browser to have a shared DOM
between the browser and the script engine based on ECMAScript5. The benefits
start with real-world performance and consistency."
Hachamovitch
said before the Chakra engine was integrated inside the browser, developers
using script engines for various languages had to communicate through the Microsoft
Component Object model (COM), which could cause performance problems. And each
script engine had its own language-specific view of the Document Object model (DOM),
which created discrepancies, he said.
However,
"In the fourth Platform Preview, we've moved the JavaScript engine inside
IE9," Hachamovitch said in his post. "With this change, communication
between the browser and script engine is now direct, which significantly
improves performance for real world websites. We now have a single DOM,
shared across all browser subsystems including JavaScript. This change ensures
a consistent and interoperable view of the document. And this single DOM
is now based on ES5 (ECMAScript 5), which prepares the entire system for the
future."
In
addition, Hachamovitch said, "The fourth Platform Preview of
Internet Explorer 9, available now, shows the opportunity of fully
hardware-accelerated HTML5. You can run new test drive samples that show modern
SVG and native JavaScript integration in action. In March, we promised to
deliver platform preview releases approximately every eight weeks. With this
installment, you will find more performance and more support for the same
markup. You'll also find many fixes to issues reported in previous Platform
Previews."
IE9
Platform Preview 4 also supports modern Scalable Vector Graphics (SVG),
improved WebKit SunSpider JavaScript benchmark results and an Acid3 test score
of 95 out of 100. That is up from 83 out of 100 in IE9 Platform Preview 3.
With
this preview, Microsoft also contributed 519 new tests to standards bodies,
which brings the total number of tests contributed during IE9 development to
2,138.
The
IE9 Platform Preview 4 can be downloaded here.
Hachamovitch
closed out his post with advice for users on how to prepare for the IE9 beta.
Said Hachamovitch:
"With
the fourth Platform Preview, we strongly recommend developers, designers and
partners to start getting your sites ready for the IE9 Beta.

Test your site in IE9 Standards Mode. This
mode provides the best performance and interoperability and will offer
additional benefits in the IE9 Beta. We suggest using the HTML5 doctype. More
details here
and here.

We recommend sending IE9 the same
standards-based markup your site sends other browsers. More details here
and here.
From the feedback so far, and our experience with sites, the best way to get
your site working in IE9 Standards Mode is to start from the same markup other
browsers receive rather than IE6, IE7 or IE8 markup.

Use featuredetection,
not browser detection to handle any cross browser differences in behavior
or feature support. This keeps your site working even as browsers change.

Please continue to report issues on Connect
if your site doesn't look or work right, and you're giving it the same code as
you're giving to other modern browsers. With IE9 Platform Preview 4, we've
fixed over 100 community-reported issues. We will fix even more between now and
the IE9 beta and want your feedback.

Consider the experience for IE9 Beta users
if you find that sending the same markup creates more issues than you can
resolve in your production site. It is possible that running
your site in Compatibility View is better for your users.

Take advantage of HTML5, CSS3,
SVG, DOM, ES5 and more ...
all described here in the developer guide. We're
excited to run the amazing experiences you bring to the web using these new
capabilities, taking advantage of hardware through IE9."

Darryl K. Taft covers the development tools and developer-related issues beat from his office in Baltimore. He has more than 10 years of experience in the business and is always looking for the next scoop. Taft is a member of the Association for Computing Machinery (ACM) and was named 'one of the most active middleware reporters in the world' by The Middleware Co. He also has his own card in the 'Who's Who in Enterprise Java' deck.